FEATURES

FAMILY

class-V pyridoxal-phosphate-dependent aminotransferase family

DESCRIPTION

Also known as ISCS_ECO57, iscS. Master enzyme that delivers sulfur to a number of partners involved in Fe-S cluster assembly, tRNA modification or cofactor biosynthesis (biotin, thiamine, molybdopterin). Catalyzes the removal of elemental sulfur and selenium atoms from cysteine and selenocysteine to produce alanine, then delivers the sulfur to an acceptor protein such as CyaY, IscU, IscX, MoaD/MoeB, ThiI, or TusA. Transfers sulfur to acceptor proteins via a transpersulfidation reaction; the flexibility of the persulfide sulfur-carrying Cys-328 allows it to reach different partners docked on the homodimer surface. May function as a selenium delivery protein in the pathway for the biosynthesis of selenophosphate. Homodimer. The homodimer interacts with CyaY, IscU, IscX, ThiI and TusA via an extended surface across both subunits centered around Cys-328. The binding sites for different partners do not necessarily overlap. Certain pairs of proteins can bind simultaneously to IscS; IscS-IscU-CyaY and IscS-IscU-IscX complexes can be isolated in vitro, but others (IscS-IscU-TusA, IscS-TusA-CyaY or IscS-IscX-TusA) complexes cannot.

EXTERNAL LINKS

iscS

Mutations

Mutation(s) distribution

Mutations table